How This Workout Works

Buh-bye, juice-cleanse trend. This real-girl slim-down is fun, it's simple, and it bleeping works. Our testers lost as many as 10 1/2 pounds and 4 inches from their waist and hips in four fly-by weeks. Even better, "you ease in with short 20-minute sessions," says FITNESS contributor Monica Vazquez, the New York Sports Clubs master trainer behind this winning firm-and-fry formula (she's the one demo'ing the moves). "You'll trim all over, sizzle fat, and still have plenty of gas left in your tank to crush it the following week." Do two circuits of the Tighten It Up series, three times a week, starting off with 12 reps per move. You'll need only a set of 5- to 15-pound dumbbells. Use the to-do chart on the following page to turn up your toning and calorie burn as you go. Check off the boxes and — bada bing! — you're 10 pounds down and totally hot.